Conventionally, a technique in which the encryption key, used to encrypt the storage device such as HDD (Hard disk drive) on the PC (personal computer), has been deleted remotely via data communication to protect the data when the PC has been lost.
However, with conventional techniques such as the one described above, if, for example, the PC is transferred to a location where data communications are unavailable or the storage device such as an HDD is removed from the PC, there is a problem that it is difficult to prevent data leakage.